Captive cap for dispensers

ABSTRACT

A captive cap for dispensers comprising a threaded tubular body or spout and a screw cap both of molded plastic composition. The spout and cap have cooperable stop lugs one of which has a camming surface. When the cap is applied at the factory, it is screwed clockwise to the full-on, sealing position. Part way through the screwing on, the lugs become engaged, and are forced past each other by a camming action which temporarily cams radially outward the lug on the screw cap and also causes a localized stretching of the adjoining wall of the cap. Thereafter the lugs constitute stops to halt the screw cap in the full-on sealing position, or in the partially unscrewed, dispensing position. The screw cap is thus held captive on the body, being turnable to various dispensing positions and to the full-on sealing position, even though it was initially applied by a turning or screwing-on movement.

United States Patent .[191

Stull @ct. 29, 1974 CAPIIVE CAP FOR DISPENSERS [76] Inventor: Morton B.Stull, c/o Stull Engraving Primary Emmljlerstanley Tonberg CQ 221 223Banta Ave" Garfield Assistant Examiner-Norman L. Stack, Jr. 07026Attorney, Agent, or Firm-H. Gibner Lehmann; K.

Gibner Lehmann [22] Filed: Nov. 20, 1972 [21] Appl. No: 308,237 [57]ABSTRACT Related US. Application Data A captive cap for dispenserscomprising a threaded [63] Continuation-impart of Ser. No. 867,199, Oct.17, tubular y P and a Screw p both of molded 19 9, abandon plasticcomposition. The spout and cap have cooperable stop lugs one of whichhas a camming surface. 52 us. c1. 222/525 When the p is pp at theflattery, it is Serewed [51] Int. Cl B67d 3/28 clockwise to the full-0n,Sealing po o Part y [58] Field of Search 222/499, 520, 521, 525; o g escrewing the g become e g g 215/40 and are forced past each other by acamming action which temporarily cams radially outward the lug on [56]Referen Cit d the screw cap and also causes a localized stretching ofUNITED STATES PATENTS the adjoining wall of the cap. Thereafter the lugsconstitute stops to halt the screw cap in the full-on sealing g gposition, or in the partially unscrewed, dispensing po- 3I351I24911/1967 StulliIIiIiIII 1:: 222 520 Sition- The Screw cap is thus heldcaptive the body, 3,370,764 2/1968 Stull 222 499 being tumable tovarious dispensing Positions and to 3 40 ,379 10 19 3 5 222/520 X thefull-on sealing position, even though it was initially 3,406,880 10/1968Stull 222/521 applied by a turning or screwing-on movement.

3,407,967 10/1968 Stull 222/521 X 0 3,598,285 8/1971 Stull 222/521 x 7Chums 11 Drawing Flgures Pmmcunme is 3.844.455

SHEH 1 M 3 YNVENTOR. -Mov on B. StuLL Pmcmmm 29 m4 3. 844.455

SHEU 2 0f 3 INVENTOR. Mqr'to n E). 5131M,

CAPTIVE CAP FOR DISPENSERS The present application is acontinuation-in-part of my copending application, Ser. No. 867,199 filedOct. 17, 1969 and having the same title; this copending application hasbeen abandoned for lack of prosecution.

CROSS REFERENCES TO RELATED APPLICATIONS AND PATENTS 1. US. Pat. No.3,319,843 dated /16/67 2. US. Pat. No. 3,339,773 dated 9/5/67 3. U.S.Pat. No. 3,351,249 dated 11/7/67 4. U.S. Pat. No. 3,407,967 dated /29/685. US. Pat. No. 3,406,880 dated 10/22/68 6. US. Pat. No. 3,370,764 dated2/27/68 7. Copending application of Morton B. Stull, Ser. No. 855,971filed 9/8/69, entitled Captive Dispensing Cap Construction", and havingcommon ownership with the present application.

BACKGROUND This invention relates to screw caps or closures fordispensers, and more particularly to closures of this type wherein thescrew cap proper is held captive on the spout or body portion. Thepresent invention is another species of the generic invention describedand claimed in my above-identified copending application.

Heretofore, dispensing caps of the captive type involved either aconstruction where the cap was initially applied to the body part bymainly an axial movement involving stripping of the threads past eachother, or a construction wherein annular detent beads were initiallyforced past each other and thereafter constituted the stop means. Theseprior caps performed satisfactorily in many circumstances but could notbe assembled by conventional rotary-type capping equipment.

SUMMARY The above disadvantage of prior captive screw caps is obviatedby the present invention, one object being the provision of an improvedcaptive screw cap wherein the initial applying of the cap proper is doneby the usual clockwise turning or screwing-on movement, and whereinthere are positive stops not only to limit the screwing-on of the capbut also to prevent the complete unscrewing and removal of the cap. Thisis accomplished by a cap construction comprising a threaded tubular bodyor spout and a screw cap both of molded plastic composition. The spoutand cap have cooperable stop lugs one of which has a camming surface.When the cap is applied at the factory, it is screwed clockwise to thefull-on, sealing position. Part way through the screwing-on, the lugsbecome engaged, and are forced past each other by a camming action whichtemporarily cams radially outward the lug on the screw cap and alsocauses a localized stretching of the adjoining wall of the cap.Thereafter the lugs constitute stops to halt the screw cap in thefull-on sealing position, or in the partially unscrewed, dispensingposition. The stop lugs normally have abutting engagement whereby thestop action is of a positive nature.

Other objects and features of the invention reside in the provision ofan improved captive screw cap as above set forth, which is especiallyeffective and reliable in its operation, simple construction, involvesfew parts, and is inexpensive to produce.

Still other feature and advantages will hereinafter appear. 1n thedrawings:

FIG. 1 is a side elevational view of the cap body part of theconstruction, with the screw cap part shown in axial section.

FIG. 2 is a top plan view of the body part.

FIG. 3 is a bottom plan view of the body part.

FIG. 4 is a side elevational view of the screw cap part of theconstruction.

FIG. 5 is a top plan view of the screw cap part.

FIG. 6 is an axial section of the screw cap part, taken on line 66 ofFIG. 5.

FIG. 7 is a side elevatioal view of the cap construction with a portionof the cap part broken away. This view illustrates the interference andcamming action between the stop lugs during assembly of the cap part tothe body part.

FIG. 8 is a transverse section taken on line 8-8 of FIG. 7.

FIG. 9 is a section similar to that of FIG. 8 but illustrating amodification of the invention.

FIG. 10 is an axial section similar to FIG. 6, of a screw cap part asused in the modification of FIG. 9.

FIG. 111 is a side elevational view of the cap construction,constituting another embodiment of the invention. The upper portion ofthe screw cap is shown in axial section.

As seen in FIGS. l-8, the improved dispensing cap construction of theinvention comprises a cap body or spout part designated generally by thenumeral 10, and a screw cap part designated generally by the numeral 12.The spout or cap body part 10 is of tubular configuration, being adaptedfor attachment to a container (not shown) as by means of internal screwthreads 14 disposed in a lower portion 16. It will be understood thatthe portion 16 of the body part may be screwed onto the threaded neck ofthe container. Containers having spouts which are integral with thecontainer walls are well known, and the body part l0, 18 could beconstituted as such.

The body part 10 has a discharge spout portion 18 terminating at itsupper or outer end in a stopper pin 20 which is supported by three webs22 defining triangular openings 24 through which the product from thecontainer can pass after traversing the spout portion. The screw cappart 12 has a central opening 26 in its tip to accommodate the topperpin 20 when the cap is screwed down to its full-on position as shown inFIG. I. A seal is thus effected by the pin 20, preventing leakage of theproduct from the cap construction. The screw cap part 12 also has anannular sealing surface 28 arranged for tight engagement with a shoulderportion 30 of the spout 18 to effect a seal below the triangularopenings 24 of the spout.

The body part 10 and screw cap part 12 have a pair of mutuallyengageable portions comprising cooperable screw thread means 32, 34respectively on said parts for moving the cap part axially as it isturned. The screw thread means comprises a helical thread element 32 ofthe buttress type, said thread element having working surfacescharacterized by a relatively small slope or angle with respect to theaxis of the cap construction. In place of the buttress type thread, ausual rounded bead-like thread can be employed. The non slopingshoulders of the buttress thread element prevent a one-way stripping,that is, prevent the cap part from being forcibly applied to the bodypart by purely axial movement In accordance with the present inventionat least one of the parts of the cap construction, and preferably bothsaid parts are constituted of resilient, yieldable plastic substancesuch as polyethylene or other suitable well-known formulation wherebyadvantage is taken of the yieldability to effect a captive or stopaction which prevents complete unscrewing and removal of the cap part12. The cap part is normally held captive on the body part after it hasbeen screwed on the latter to the full-on position or at least past anintermediate position representing the full-open or unstopped conditionof the cap.

The helical thread elements 32, 34 function to effect downward (asviewed in FIGS. 1 and 7) axial movement of the cap part 12 as the latteris turned in a clockwise direction (as viewed from the top) and appliedto the body part 10. However, if during such screwing-on operation thecap part 12 should encounter some momentary or yieldable obstruction toits axial movement, as by cooperable lugs shortly to be described, oneor both of the closure parts can yield radially and become temporarilyoval or out-of-round in cross section as the cap part overcomes theobstruction. This is shown in FIG. 8. When the temporary obstruction toturning and axial movement of the cap part ceases, the parts will springback and be restored to their initial, normal or non-yielding,non-deformed condition. The lug structure which provides the temporaryobstruction is described further below.

The body part has a second or additional thread element, comprising acam track 36 provided around the base of the spout portion 18, said camtrack being cooperative with an interior stop lug 38 provided within thebottom rim 40 of the cap part 12. The lug 38 rides on the cam track 36and imparts a positive outward axial movement to the cap part as thelatter is turned in unscrewing direction.

In accordance with the invention the cap and body parts have a secondpair of mutually engageable portions. comprising cooperable stop lugs,one of which is constituted as the lug 38, said lugs providing theabovementioned temporary obstruction. The second lug, disposed on thespout portion 18 of the body part, is designated 42 and is disposed atthe high end of the cam track 36. The stop lug 42 has opposite surfaces44, 46 which are respectively engageable with opposite surfaces 48, 50of the stop lug 38. Aslo, in accordance with the invention, the lug 42has a camming portion 52 constituting a face which slopes with respectto the direction of movement to be engaged by the stop lug 38 of the cappart 12 as the latter is screwed onto the body part 10, such engagementbeing illustrated in FIGS. 7 and 8. The engagement with the sloping face52 constitutes a momentary obstruction or impediment to the downwardturning or screwing-on movement of the cap part 12 and as such movementis forcibly continued the parts 10 and 12 will yield and the lug 38 willride past the outside of the lug 42 as effected by the sloped face 52.This action will cause a deformation of the wall of the cap 12 and moreparticularly of the rim 40 thereof, so that said rim assumes somewhat ofan egg shape. Also, the rim 40 adjacent the lug 38 will experience alocalized temporary stretching of the plastic material, until the lug 38becomes disengaged from the lug 42. Referring again to FIGS. 7 and 8, asthe clockwise turning movement of the cap part 12 is continued, the stoplug 38 thereof will be forced completely past the lug 42 of the bodypart 10 and upon reaching the surface 44 of the lug 42 it will snapradially inward so as to engage the high portion of the cam track 36.This snapping inward of the lug 38 and adjoining wall of the cap part 12is due to the tendency for the deformed parts to resume the non-yieldingor unsprung condition.

Upon the lug 38 of the cap part being cammed past the lug 42 of the bodypart, the screwing-on movement of the cap part can be continued until itreaches the full-on position of FIG. I.

It will now be understood that as the consumer unscrews the cap part 12to avail himself of the product, the lug 38 can be brought intoengagement with the stop surface 44 of the lug 42, whereby furtherunscrewing of the cap part 12 will be prevented. For the full-onposition of the cap part, the surface 48 of the lug 38 is engaged withthe surface 46 of the lug 42, whereupon there exist positive stopsdefining not only the full-on position of the screw cap but also thefull-open position of the same.

For different intermediate positions of the cap part 12, the extent ofclosing of the discharge opening 26 by the sealing pin 20 can be varied,thereby providing a degree of control of flow of the liquid product fromthe container.

A modification of the invention is illustrated in FIGS. 9 and 10. Inthese figures the spout or cap body part 10a has a lug 42a which is notprovided with the sloping face; instead the lug 380 on the cap part 120has the sloping face 52a at its lower portion. During the screwing on ofthe cap part 12a, the sloping face 52a of the lug 38a will engage thelug 42a of the spout part, and this will cause the lug 38a to rideoutside of the lug 42a as shown in FIG. 9. After the lug 38a has beenforced past the lug 42a, the opposite surfaces 48a and 50a of the lug30a will be cooperable with the corresponding surfaces 440 and 46a ofthe lug 42a to prevent removal of the cap part and to limit thescrewing-on movement of the same in the manner already described abovein connection with the cap part 12.

As seen in FIG. 10, the cap part 12a has an orifice opening 26a, screwthreads 34a and a bottom rim 40a similar to the corresponding portionsof the cap part 12.

As with the embodiment of FIGS. I-8, the cap and body parts 12a, arepreferably molded of resilient plastic substance, and both parts yieldso as to become slightly egg-shaped or out-of-round as shown in FIG. 9,in order to permit the lug 38a to bypass the lug 42a during thescrewing-on operation of the cap part.

In FIG. 8 it will be noted that the surfaces 44, 52 of the lug 42 lie inplanes which are substantially parallel to the axis of the body part 10.Also, surfaces of the lug 38 which are cooperable with the surfaces 44,52 lie in plane which are substantially parallel to the axis of the bodypart 10.

In FIG. 9 the surfaces 44a and 46a of the lug 42a lie in planes whichare substantially parallel to the axis of the body part 10a. Further,the surfaces of the lug 38a which cooperate with the surfaces 440 and46a lie in planes which are substantially parallel to the axis of thebody part 10a. By such disposition of the cooperable surfaces of thecap-captivating lugs a unique and surprisingly new mode of operationoccurs when assmebling the cap part to the body part, since theyieldable wall of either one of said parts which is resilient and whichmoves radially outward or inward constitutes a circumferentiallylocalized wall portion, with the result that the entire circumference ofthe wall is not required to either simultaneously expand or contract inorder to permit bypassing of the lugs. This constitutes an importantfeature of the invention, since it makes for a softer and more yieldablescrew-on action.

It is to be noted from FIGS. 8 and 9 that the extent of engagement ofthe lugs 38, 42 (38a, 42a) corresponds to a small fractional part of thearcuate extent of the circumference. That is to say, the lugs engage onenother along an arc of substantially less that 90 during the bypassthereof.

Another embodiment of the invention is illustrated in FIG. 11, whereinthere is shown a tubular body part 18b having a double helical'thread32b of rounded or convex cross-configuration. The screw cap part 12b hasa cooperable double thread formation 34b mating with the threads 32b. Bythis arrangement a faster lead is had, in response to turning movementof the cap 12b. The tubular body 18b includes a lug 42b, 44b with asloping surface 52b. The screw cap 12b has a cooperable lug 38b which isshown in dotted outline in H0. ll.

The connstruction of FIG. 11 has the advantage that a more securescrewing action is provided by the rounded nature of the screw threadsand by the fact that a double thread is provided, resulting in a moreuniform distribution of the axial forces as the cap 12b is screwed down.This insures a positive by-passing of the lug 42b, 44b by the cap lug38b.

It will now be understood from the foregoing that l have provided anovel and improved captive dispensing cap construction wherein the cappart is threaded onto the body part by a conventional screwing-onmovement, and wherein after the cap part reaches its full-on position,it will be prevented and held from complete removal by a positive stop.The unscrewed or dispensing position of the cap part 12 and also thefull-on or sealing position of the part are determined by positiveactionstop lugs, and the cap part is held captive on the body part once it hasbeen applied thereto and screwed past the full-open dispensing position.

Variations of the structures shown are possible without departing fromthe spirit of the invention.

I claim:

I. A captive dispensing cap construction comprising, in combination:

a. a tubular body part adapted to be carried by a container and having adischarge spout,

b. a screw cap part carried by said body part and surrounding saiddischarge spout.

c. said cap and body parts having two pairs of mutually engageableportions,

d. one pair of mutually engageable portions comprising cooperable screwthread means respectively on said parts, for moving the cap part axiallyon the body part as the cap part is turned,

e. the other pair of mutually engageable portions comprising cooperablestop lugs disposed respectively on the body and cap parts only atcircumferentially localized points, said lugs having a plurality of setsof mutually engage-able surfaces which are disposed in planessubstantially parallel to the axis of the tubular body.

f. one set of said mutually-engageable surfaces of the lugs becomingengaged and acting in a manner to halt the turning of the cap part asthe latter is screwed toward its full-on position on the body part,

g. another set of surfaces of the said lugs becoming engaged and haltingthe opposite turning of the cap part as the latter is unscrewed throughpart of a revolution from said full-on position,

b. one of the mutually-engageable surfaces of said stop lugs having asloping camming face with respect to the other stop lug, to cam one lugradially outwardly and facilitate bypass of the lugs as the cap part isscrewed. onto the body part,

. at least one of said parts having lug-carrying wall portion which isresilient and yieldable in a radial direction and capable of localizedstretching to enable the stop lug on the cap part to be forced past theoutside of the stop lug on the body part as the cap part is applied tothe body part and screwed toward its full-on position,

j. said lugs engaging one another along an arc of substantially lessthan during said bypass of the lugs.

2. A cap construction as in claim 1, wherein:

a. the lug-carrying wall portion which is resilient and capable oflocalized stretching is on the cap body part.

3. A cap construction as in claim 1, wherein:

a. the lug-carrying wall portion which is resilient and capable oflocalized stretching is on the cap part.

4. A cap construction as in claim 1, wherein:

a. both the cap part and the cap body part have lugcarrying wallportions which are resilient and yieldable and capable of localizedstrtching.

5. A cap construction as in claim 1, wherein:

a. the stop lug on the body part has the sloping face.

6. A cap construction as in claim 1, wherein: a. the stop lug on the cappart has the sloping face.

7. A cap construction as in claim 1, wherein:

a. the cooperable screw means on said parts comprise a double thread onthe body part and a double thread on the cap part, and

b. said double threads being of rounded cross-

1. A captive dispensing cap construction comprising, in combination: a.a tubular body part adapted to be carried by a container and having adischarge spout, b. a screw cap part carried by said body part andsurrounding said discharge spout, c. said cap and body parts having twopairs of mutually engageable portions, d. one pair of mutuallyengageable portions comprising cooperable screw thread meansrespectively on said parts, for moving the cap part axially on the bodypart as the cap part is turned, e. the other pair of mutually engageableportions comprising cooperable stop lugs disposed respectively on thebody and cap parts only at circumferentially localized points, said lugshaving a plurality of sets of mutually engageable surfaces which aredisposed in planes substantially parallel to the axis of the tubularbody. f. one set of said mutually-engageable surfaces of the lugsbecoming engaged and acting in a manner to halt the turning of the cappart as the latter is screwed toward its full-on position on the bodypart, g. another set of surfaces of the said lugs becoming engaged andhalting the opposite turning of the cap part as the latter is unscrewedthrough part of a revolution from said full-on position, h. one of themutually-engageable surfaces of said stop lugs having a sloping cammingwith respect to the other stop lug, to cam one lug radially outwardlyand facilitate bypass of the lugs as the cap part is screwed onto thebody part, i. at least one of said parts having lug-carrying wallportion which is resilient and yieldable in a radial direction andcapable of localized stretching to enable the stop lug on the cap partto be forced past the outside of the stop lug on the body part as thecap part is applied to the body part and screwed toward its full-onposition. j. said lugs engaging one another along an arc ofsubstantially less than 9* during said bypass of the lugs.
 2. A capconstruction as in claim 1, wherein: a. the lug-carrying wall portionwhich is resilient and capable of localized stretching is on the capbody part.
 3. A cap construction as in claim 1, wherein: a. thelug-carrying wall portion wHich is resilient and capable of localizedstretching is on the cap part.
 4. A cap construction as in claim 1,wherein: a. both the cap part and the cap body part have lug-carryingwall portions which are resilient and yieldable and capable of localizedstrtching.
 5. A cap construction as in claim 1, wherein: a. the stop lugon the body part has the sloping face.
 6. A cap construction as in claim1, wherein: a. the stop lug on the cap part has the sloping face.
 7. Acap construction as in claim 1, wherein: a. the cooperable screw meanson said parts comprise a double thread on the body part and a doublethread on the cap part, and b. said double threads being of roundedcross-sectional configuration.